Due to advances in communication systems, various types of wireless terminals have been introduced to consumers, such as companies and individuals. A current mobile communication system has affiliated with 3rd generation partnership project (3GPP), for example, Long Term Evolution (LTE), LTE-Advanced (LTE-A), and the like. Such a current mobile communication system has been required to transmit and receive a large amount of data at a high speed through a wireless communication network, as fast as transmission in a wired communication network. Accordingly, there is a demand to develop technology for wirelessly transmitting a large amount of data at a high speed as fast as transmission in a wired communication network. To this end, data transmission technology using a plurality of cells or small cells has been introduced. For example, the carrier aggregation technology is a technology that aggregates one or more component carriers and performs the transmission/reception of data to improve a data transmission/reception rate. A large amount of data may be processed at a high speed since an available frequency is increased from the perspective of a terminal.
However, there are drawbacks. For example, resources such as frequency for a mobile communication network are limited, and the number of mobile communication subscribers is abruptly increasing. Accordingly, there is limitation in improving a transmission/reception rate.
Further, respective frequency bands are used by different wireless communication systems based on a policy. Accordingly, mutual compatibility is low.